Artificial ventilation mask with PPCO2 reducer and/or epinephrine source in mask

ABSTRACT

A mask for artificial ventilation and cardiopulmonary resuscitation is disclosed and claimed. The mask comprises a compartment which contains a material that alters the composition of the gas which is exhaled by the rescuer into the victim. The mask also provides a physical barrier between the victim and rescuer to aid in preventing the transmission of disease.

BACKGROUND OF THE INVENTION

Artificial respiration and cardiopulmonary resuscitation (CPR) arelife-saving measures that supply necessary oxygen (O₂) to the blood andtissues of a patient who has experienced a cessation of normal breathingand a regular heart beat. Artificial respiration provides O₂ to a victimthat has stopped breathing. Typically, artificial respiration caninvolve mouth-to-mouth ventilation (MTMV). In MTMV oxygen is provided tothe victim through the expiration of the rescuer. To initiate the MTMVprocedure, the rescuer opens the air-way of the victim by tilting thehead of the victim back and pulling the jaw forward. The rescuer forms aseal over the mouth, or mouth and nose, of the victim with the rescuer'smouth. The rescuer then exhales into the mouth of the victim. Therescuer's exhalation is forced into the lungs of the victim and providesthe victim with needed O₂.

Cardiopulmonary resuscitation combines mouth-to-mouth ventilation withcompressions to the thorax or chest. The chest compressions push bloodthrough the circulatory system to provide oxygen to the tissuesincluding the heart and to remove carbon dioxide and stimulate theheart. Both procedures are used to restore normal respiratory andcirculatory function or to sustain the life of a victim until adequatemedical attention can be obtained.

References to procedures for artificial respiration and mouth-to-mouthventilation have been noted for thousands of years; CPR, however, hasonly become an accepted practice within about the last 30 years(Hermreck, 1988; BeBard, 1980). Today, both procedures are mainstays inemergency medical situations.

Both CPR and artificial respiration can involve mouth-to-mouth contactbetween rescuer and victim. Therefore, concerns have arisen as to thepossible transmission of communicable diseases during these life-savingprocedures. Concerns have heightened recently with the emergence ofAIDS. Although there have been no reported incidences of health careworkers becoming HIV-positive after administering CPR to an AIDSpatient, a recent survey reports that 93% of nurses surveyed wouldhesitate to give CPR to a patient with AIDS (Michael et al, 1992). In asurvey of CPR instructors, 71% said that their attitudes about providingCPR to strangers have changed as a result of the AIDS epidemic. Fortypercent of those instructors surveyed who had administered CPR in theprevious three years admitted that they did hesitate beforeadministering CPR to a victim, and over half cited a fear of disease asthe cause of that hesitation (Ornato et al., 1990).

To avoid physical contact during artificial respiration and CPR, manyfirst-aid kits now include a mask that provides a physical barrierbetween the mouth of the victim and the mouth of the rescuer. There arethree basic types of masks routinely used for this purpose. U.S. Pat.No. 5,095,898 describes one such mask. The three main types arebag-valve masks, hand-held masks, and lay-on barrier masks. Thebag-valve mask, or manual resuscitation bag, has a molded facepiecewhich is contoured to cover the nose and mouth of the victim. Thefacepiece is impermeable to air so that if properly sealed all airadministered to the victim is ultimately forced into the upper airway ofthe victim and then into the lungs. A bag is attached to the facepieceand holds the air for ventilation. The bag-valve mask eliminates closecontact between the rescuer and victim, but can prove cumbersome for asingle rescuer trying to pump the bag and keep the mask sealed tightlyover a victim's nose and mouth. Further, bag-valve masks usually deliversub-optimal ventilation volumes, probably due to the lack of a properseal.

Hand-held masks have a facepiece similar to the contoured facepiece ofthe bag-valve mask, but do not have a bag for ventilation. The rescuerexhales directly into an orifice in the mask. Hand-held masks thereforerequire more intimate contact between the rescuer and victim, but stillprovide a physical barrier.

Lay-on barrier masks are pliable sheets that act as a physical barrierbetween the mouth of the victim and the mouth of the rescuer. Lay-onbarrier masks provide the greatest ventilation volume of the three typesof masks. However, lay-on masks do not provide an adequate barrier toprevent contamination should a victim vomit into the mask. Further,these masks can only be used for mouth-to-mouth ventilation and cannotbe connected to a bag for manual ventilation.

Because of the risks associated with mouth-to-mouth contact, debateshave arisen as to the necessity of ventilating the victim during CPR.Ventilation has been found to be necessary, however, for successfulresuscitation (Idris et al., 1994a; Idris et al, 1994b). Properventilation affects the acid-base balance as well as oxygenation of theblood of the victim, and assists in successful recovery (Idris et al,1994b; Idris et al., 1992). Recent studies have shown that hypoxia(below normal levels of O₂) and hypercarbia (above normal levels of CO₂)in ventilating gas have independent adverse effects on resuscitationfrom cardiac arrest (Idris et al., 1994a; Idris et al., 1994b). The airwe normally breath is approximately 21% O₂ and 0.033% CO₂. Thecomposition of the air or gas exhaled by a rescuer is approximately17-18% O₂ and 3.5-4% CO₂ (Wenzel et al., 1994a; Wenzel et al., 1994b).Percentages of CO₂ can be higher in one-rescuer CPR as opposed totwo-rescuer situations. This is probably due to the greater work loadthat the single rescuer performing CPR must endure. Therefore, the gascomposition delivered by a rescuer to a victim during CPR is bothhypoxic and hypercarbic when compared to the air we normally breath.High levels of CO₂ have further been found to cause the inhibition ofspontaneous contractions of myocardial cells in culture. This suggeststhat high levels of CO₂ may be dangerous to the heart (Becker et al.,1993).

Anesthesia machines use certain chemicals to remove carbon dioxide fromgases given to a patient. Pasternak (U.S. Pat. No. 4,491,130) describesan emergency respirator which removes CO₂ from inhaled air when thesurrounding air becomes climatically unfavorable. The respirator ofPasternak is for a user who is breathing independently. The respiratorcomprises a heat storage mass which captures body heat lost by the userduring exhalation, and stores the heat to be supplied back to the userupon inhalation. The respirator provides the user with breathable airand prevents heat loss during respiration.

BRIEF SUMMARY OF THE INVENTION

The subject invention concerns a mask for use in artificial respirationand/or cardiopulmonary resuscitation (CPR). In a preferred embodiment,the mask of the subject invention is compact and placed over the mouthand nose of a victim in respiratory or cardiac arrest. The mask has anorifice for gas delivery through which the exhalation of the rescuer isdirected into the upper respiratory tract of the victim and then intothe lungs. Gas exhaled by the rescuer passes over, or through, acartridge or compartment which contains material that alters thecomposition of the exhaled gas before it reaches the respiratory tractof the victim. Specifically, the material in the compartment removescarbon dioxide from the exhaled gas. In one embodiment the mask alsoenriches the gas with oxygen. The mask of the subject invention canfurther comprise an opening or valve to facilitate exit of gas exhaledby the victim.

One aspect of the subject invention pertains to a cartridge, orcompartment, configured to be inserted into, or attached to, ventilationmasks which lack gas altering capabilities. The compartment hascontained therein a material which can advantageously alter the chemicalcomposition of exhaled gas which comes in contact with the material.Specifically, the material can reduce the mount of carbon dioxide in thegas. The material can be, for example, calcium carbonate.

The subject invention provides an artificial ventilation mask which canbe used in business locations, by emergency medical systems, onambulances, police vehicles, and fire trucks, at mass gatherings (e.g.,sporting events), and by lay public individuals. The mask improves thechemical composition of the gas which reaches the respiratory tract ofthe victim after being exhaled by the rescuer. In a preferred embodimentthe mask removes carbon dioxide of exhaled gas and provides a physicalbarrier against disease.

BRIEF SUMMARY OF THE FIGURES

FIG. 1 shows one embodiment of the mask of the subject invention whereinthe chemical compartment is an integral part of the mask.

FIG. 2 shows an embodiment of the mask wherein the chemical compartmentis attached to the delivery orifice of the mask.

DETAILED DESCRIPTION OF THE INVENTION

The subject invention concerns a mask for artificial ventilation and/orCPR. In a preferred embodiment, the mask comprises a compartment orcartridge containing a material that alters the composition of the gasexhaled by the rescuer and received by the victim. As used herein,reference to the "chemical compartment" includes a compartment builtinto a ventilation mask for the purpose of holding a material which canremove carbon dioxide and/or enrich for oxygen. Reference to "chemicalcompartment" further includes a cartridge which can be fitted onto orinto a mask and which holds a material for removing carbon dioxideand/or enriching oxygen. The compartment and/or the material therein maybe of any shape or size sufficient to effect the desired modulation ofthe chemical composition of the gas exhaled by the rescuer.

One embodiment of the mask of the subject invention is a hand-held typemask shown in FIGS. 1 and 2. The mask comprises a barrier piece 12, adelivery orifice 14, and a chemical compartment 16. When the mask isused the barrier piece is placed over the mouth, or the nose and mouth,of the victim to exclude air from external sources and to direct theexhalation of the rescuer into the upper respiratory tract of thevictim. The rescuer exhales through the delivery orifice which directsthe exhaled gas over or through the chemical compartment. Contactbetween the exhaled gas and the material in the chemical compartmentresults in the removal of carbon dioxide. The material may also enrichthe oxygen content. Additionally, the barrier piece provides a physicalseparation between the mouth of the victim and the mouth of the rescuerto avoid the transmission of communicable disease.

In a specific embodiment of the subject invention, the barrier piece 12,as shown in FIGS. 1 and 2, is a molded cup-like structure formed to fitover the nose and mouth of the victim to ensure an adequate seal betweenthe mask and the victim and to provide the victim maximum ventilationvolume. In one embodiment, the barrier piece can comprise a flexibleedge portion 18 which comfortably and snugly fits against the victim'sface. This flexible edge portion may be, for example, plastic, rubber,or an air-inflated bladder made from plastic, rubber, or a likematerial. Straps, belts, or bands can be affixed to the mask to securethe mask to the victim and assist in providing an adequate seal.

The barrier piece 12 is preferably impervious to air and most preferablyalso impervious to infectious agents. A barrier piece for a lay-on typemask must be pliable and be able to conform to and seal with the naturalcontours of the mouth of the victim. Plastic or vinyl sheets aresufficiently pliable and can be made to resist tearing. Hand-held masks,such as the mask illustrated in FIG. 1, should have a barrier piece madeof a rigid or stiff material that can be molded to a smooth contour.Materials that can be used to form the cup-like barrier piece of themask of the preferred embodiment include soft plastics and hardplastics, fiberglass, plexiglass, metal, and the like. If the barrierpiece is to be reused, the material of the barrier piece should be ableto withstand decontamination procedures such as treatment with harshchemicals or autoclaving. The barrier piece can be made of a materialthat is either transparent or opaque. Transparent materials allow therescuer to check the seal of the barrier piece on the victim and todetermine whether the victim has vomited into the mask or the passage isotherwise blocked.

The delivery orifice 14 provides a passage through which the exhaled gasof the rescuer enters the mask. The delivery orifice can be a simpletube hermetically sealed to the barrier piece. The tube may be less thanan inch long or may be a foot or more in length. The tube can bepositioned on the mask so that the exhaled gas is directed across orthrough the chemical compartment 16 and into the mouth and nose of thevictim. The direction of flow of the gas will depend upon the shape andconfiguration of the chemical cartridge and can be modified as necessaryby one skilled in the art utilizing the teachings provided herein. Theexhaled gas can be directed directly into and through a cartridge and/ormay be directed across a narrower, fiat cartridge, thus ensuring theexhaled gas comes into contact with maximum surface area of the chemicalcompartment. Further, the delivery orifice 14 can be fitted with aspecial mouthpiece to ensure that the delivery orifice is being held inthe mouth firmly and all exhaled air is being directed into the mask.Typically, the delivery orifice may be about 15-30 mm in diameter. Amouthpiece on the delivery orifice 14 also assists a rescuer incontrolling the fit and seal of the mask on the victim.

The sides of the chemical compartment should allow exhaled gas to enterthe compartment, contact the material enclosed therein, and exit throughthe mask into the upper respiratory tract and lungs of the victim. Thus,the sides of the compartment through which exhaled gas enters and leavesthe compartment must be able to contain the material within but mustalso allow the passage of the exhaled gas. The material from which thecompartment is made may either be gas permeable or may be a fine meshwhich allows the passage of gas but not the passage of the gas-alteringmaterial.

A further advantage of the subject invention is the regulation of gasflow from the rescuer to the victim. The gas flow is regulated becausethe rescuer must force the exhaled gas through the material in thechemical compartment.

In a preferred embodiment the chemical compartment contains materialsthat remove carbon dioxide. For example, chemicals such as calciumcarbonate absorb CO₂ from the exhaled gas, reducing the partial pressureof CO₂. The relative partial pressure of O₂ can be thus increased. Thechemical compartment can also comprise a material that releases oxygenas the exhaled gas passes over or through the material. For example, thematerial may release oxygen when exposed to moisture. The moisture maybe provided by the exhaled gas itself or may be generated as the CO₂ inthe exhaled gas is chemically removed. For example, calcium bicarbonatewill release water when exposed to exhaled carbon dioxide. Carbondioxide is removed in the process. The water produced according to thisreaction can then lead to the release of oxygen upon reaction of thewater with a chemical such as manganese dioxide or manganesepercarbonate.

The chemical compartment can also comprise an indicator to show when theCO₂ absorbing properties of the material is diminished. For example, theindicator can comprise a paper strip impregnated with a pH sensitive dyeor any other means which gives a rescuer a visual indication of the CO₂absorption capabilities of the chemicals in the compartment at any giventime. The indicator strip can also comprise printed information andthereby serve as a means of quality control or a dating system to ensureeach mask will provide the recipient maximum effect.

In one embodiment, the mask of the subject invention further comprisesan opening which allows the victim's exhaled gas to exit the maskwithout passing over or through the chemical compartment. Return of thisgas through the chemical compartment provides no advantage to the victimsince the victim does not rebreathe the air, and it unnecessarily spendsthe chemicals within the compartment. The opening 22 or an equivalentvalve can be placed on the barrier piece 12 as shown in FIG. 1. Thevalve can be placed at the base of the delivery orifice 14 in anembodiment where the cartridge is the type that is positioned within thetube of that orifice. In either of these embodiments the hole (or holes)could be covered by the rescuer's hand or fingers as the rescuer exhalesand forces gas through the mask into the upper respiratory tract andlungs of the victim.

In a further embodiment of the subject invention, the gas-alteringchemicals can be contained in a cartridge which can be attached to orfitted into an existing mask. The chemical cartridge can be attached toa variety of masks in a number of ways as would be appreciated by oneskilled in the art having the benefit of the teachings provided herein.The cartridge should be attached to the mask in a manner to ensuremaximum contact of the rescuer's exhalation with the gas-alteringchemicals. A cartridge can be formed to fit snugly against the orificeof hand-held masks and can be held in place by friction or tension.Masks can be specially constructed to comprise brackets or pockets tohold the chemical cartridge. The cartridge can be shaped to fit into andbe retained by the tube of the delivery orifice. Lay-on masks cancomprise pockets into which a bean-bag like chemical cartridge can beslipped, wherein the free-form of the cartridge conforms to the victim'smouth to ensure that all gas entering the victim has passed through thecartridge.

In a preferred embodiment, as shown in FIG. 1, the chemical cartridgehas an outer perimeter shape approximating an inner shape of the maskjuxtaposed to the gas delivery tube and wherein the chemical cartridgeis positioned within the mask juxtaposed to the gas delivery tube.

In an additional embodiment of the subject invention, the chemicalcompartment can comprise medications which can be volatilized anddelivered through the pulmonary route during rescue. Such medicationswould include, but not be limited to, medications to treat asthma orheart failure, or other conditions which can cause cessation or extremedifficulty in breathing. Such medications could include, for example,epinephrine. In this embodiment of the subject invention the mask wouldpreferably comprise a vane which would prevent any backflow of gas.

It should be understood that the examples and embodiments describedherein are for illustrative purposes only and that various modificationsor changes in light thereof will be suggested to persons skilled in theart and are to be included within the spirit and purview of thisapplication and the scope of the appended claims.

REFERENCES

Michael, A. D., and J. S. Forrester (1992) "Mouth-to-Mouth Ventilation:The Dying Art," Amer. J. Emer. Med. 10(2):156-161.

Ornato, J. P., L. F. Hallagan, S. B. McMahon, E. H. Peeples, and A. G.Rostafinski (1990) "Attitudes of BCLS Instructors About Mouth-to-MouthResuscitation during the AIDS Epidemic," Ann. Emer. Med. 19(2):151-156.

Hermreck, A. S. (1988) "The History of Cardiopulmonary Resuscitation,"Amer. J. Surgery 156:430-436.

DeBard, M. L. (1980) "The History of Cardiopulmonary Resuscitation,"Ann. Emer. Med. 9(5):273-275.

Becker, L., A. Idris, Z. Shao, C. Lir, J. Art, S. Schorer, M. Goodmanand R. Zak (1993) "Inhibition of Spontaneous Cardiomyocyte Contractionsby Carbon Dioxide," Abstract 1203 Circulation 88(Suppl.):I-225.

Idris, A. H., E. D. Staples, D. J. O'Brien, R. J. Melker, M. J. Rush, K.D. DelDuca and J. L Falk (1994a) "The Effect of Ventilation on Acid-BaseBalance and Oxygenation in Low Blood Flow States," Crit. Care Med.22:1827-1834.

Idris, A. H., L. B. Becker, R. S. Fuerst, V. Wenzel, W. J. Rusch and R.J. Melker (1994b) "The Effect of Ventilation on Resuscitation in anAnimal Model of Cardiac Arrest," Circulation 90:3063-3069.

Wenzel, V., A. H. Idris, M. J. Banner, R. S. Fuerst, and K. J. Tucker(1994a) "The Composition of Gas Given by Mouth-to-Mouth VentilationDuring CPR," Chest 106:1806-1810.

Idris, A. H., R. J. Melker, K. D., DelDuca, E. D. Staples, D. J.O'Brien, W. Rush, J. L. Falk (1992) "The Effect of Ventilation of pH,PCO₂ and End-Tidal Carbon Dioxide During Low Blood Flow States,"Abstracts from the 65th Scientific Sessions of the Circulation 1992,Circulation, Suppl. I 86(4):I-547.

Idris, A. H., R. S. Fuerst, V. Wenzel, L. B. Becker, D. J. Orban and M.J. Banner (1993b) "Does Hypoxia or Hypercarbic Acidosis IndependentlyAffect Survival from Cardiac Arrest?" Circulation 88(Suppl.):I-225.

Wenzel, V., A. H. Idris, M. J. Banner, R. S. Fuerst, and D. J. Orban(1994b) "Exhaled Gas Composition of Mouth-to-Mouth Ventilation DuringCardiopulmonary Resuscitation (CPR)," Crit. Car. Med. 22:A-133.

I claim:
 1. A mask for artificial ventilation or cardiopulmonaryresuscitation to deliver exhaled gas from a rescuer to a victim, whereinsaid mask comprises:(a) a barrier piece to cover the mouth, or the noseand mouth, of the victim, (b) a gas delivery tube, and; (c) acompartment comprises a material which is able to alter the chemicalcomposition of the delivered gas, wherein said compartment comprises achemical cartridge, said chemical cartridge having an outer perimetershape approximating an inner shape of said mask juxtaposed to said gasdelivery tube, said chemical compartment positioned within said maskjuxtaposed to said gas delivery tube; and (d) a means for a rescuer toexhale gas into said gas delivery tube, while said mask is covering amouth, or nose and mouth, of a victim, such that the gas can enter theupper respiratory tract and lungs of said victim,wherein saidcompartment is positioned such that gas exhaled by the rescuer into saidgas delivery tube contacts said gas-altering material before enteringthe upper respiratory tract and lungs of a victim; and wherein thematerial within said compartment alters the composition of saiddelivered gas by decreasing the partial pressure of carbon dioxide insaid gas.
 2. The mask, according to claim 1, wherein the material withinsaid compartment alters the composition of said delivered gas byincreasing the partial pressure of oxygen in said gas.
 3. The mask,according to claim 1, wherein the material in said compartment comprisesa carbonate.
 4. The mask, according to claim 3, wherein the material insaid compartment comprises calcium carbonate.
 5. The mask, according toclaim 1, wherein said barrier piece is molded to conform to the nose andmouth of a victim.
 6. The mask, according to claim 1, wherein a materialwithin said compartment releases oxygen when contacted by the exhaledgas of a rescuer.
 7. The mask, according to claim 6, wherein thematerial within said compartment which releases oxygen is selected fromthe group consisting of manganese dioxide and manganese percarbonate. 8.The mask, according to claim 1, wherein the material which alters thegas composition comprises calcium carbonate and manganese dioxide. 9.The mask, according to claim 1, which comprises a hole or valve to allowgas exhaled by a victim to leave the mask without contacting thegas-altering material.
 10. The mask, according to claim 1, wherein saidmaterial which alters the gas composition comprise a medicament.
 11. Acompartment which can be fitted into or onto a mask for use inartificial ventilation or cardiopulmonary resuscitation wherein saidcompartment encloses a material which can alter the chemical compositionof a gas exhaled by a rescuer, wherein said material alters the chemicalcomposition of the gas by adding a medicament to the gas.
 12. A methodfor administering a exhaled gas into the upper respiratory tract andlungs of a victim who is having trouble breathing or who has stoppedbreathing wherein said method comprises providing a mask for artificialventilation or cardiopulmonary resuscitation to deliver exhaled gas froma rescuer to a victim, wherein said mask comprises:(a) a barrier pieceto cover the mouth, or the nose and mouth, of the victim, (b) a gasdelivery tube, and; (c) a compartment comprising a material which isable to alter the chemical composition of the delivered gas, whereinsaid compartment comprises a chemical cartridge, said chemical cartridgehaving an outer perimeter shape approximately an inner shape of saidmask juxtaposed to said gas delivery tube, said chemical compartmentpositioned within said mask juxtaposed to said gas delivery tube; and(d) a means for a rescuer to exhale gas into said gas delivery tube,while said mask is covering a mouth, or nose and mouth, of a victim suchthat the gas can enter the upper respiratory tract and lungs of saidvictim,wherein said compartment is positioned such that gas exhaled bythe rescuer into said gas delivery tube contacts said gas-alteringmaterial before entering the upper respiratory tract and lungs of avictim; and wherein the material within said compartment alters thecomposition of said delivered gas by decreasing the partial pressure ofcarbon dioxide in said gas, and wherein said method further comprisesexhalation, by a rescuer, into said mask, which mask directs saidexhaled gas into the upper respiratory tract and lungs of a victimwherein said gas exhaled by a rescuer contacts said material whichalters the chemical composition of said exhaled gas by decreasing thepartial pressure of carbon dioxide.
 13. The method, according to claim12, wherein said chemical compartment further comprises a medicamentwhich is epinephrine.